Heat sinks for electric lamps



Nam 17, 1970 J. J. FENN HEAT SINKS FOR ELECTRIC LAMPS 2 Sheets-Sheet 1 Filed Aug. 5, 1968 INVENTOR 7 ATTORNEY Nov. 17, 1970 J. JQFENN 3,541,492

HEAT s mxs FOR ELECTRIC LAMPS Filed Aug. '5. 1968 2 Sheets-Sheet w 44 32 30 Hww 56.4. mm zw- QM INYINTOR AT'TORNEY United States Patent 3,541,492 HEAT SINKS FOR ELECTRIC LAMPS John James Fenn, Tottenham, England, assignor to The Benjamin Electric Limited Filed Aug. 5, 1968, Ser. No. 750,328 Int. Cl. H0lr 13/14 US. Cl. 33952 4 Claims ABSTRACT OF THE DISCLOSURE A lamp holder for a tubular electric lamp of the type having a cap at one end or at each end. The lamp holder has a socket for the lamp end cap and two pivoted arms mounted on the body of the holder, the arms being springbiased to engage the lamp and act as heat sinks. The positions of the arms relative to the holder body are axially adjustable to allow for tolerance variations in the lamp dimensions. A shorter or longer lamp can be conveniently accommodated by shifting the holder as a whole. The heat sink arms will always engage the lamp near one end, which is where it is required to cool the lamp.

The present invention relates to electric lamp holders for tubular electric lamps.

It is an object of the invention to provide a unitary tubular electric lamp holder of simple construction which can be used with a lamp of any length, and provide a heat sink to cool the end of the lamp which will correctly engage the lamp end regardless of tolerance variations in the lamp.

According to the invention, there is provided an electric lamp holder for a tubular electric lamp comprising a support for one end of the lamp and at least one heatconductor member movably mounted on the support and resiliently biased to engage the lamp at or near said one end thereof and dissipate heat away therefrom.

The invention will be described by way of example with reference to the accompanying drawings, wherein:

FIG. 1 is a perspective view of an electric lamp holder embodying the invention, showing one side and the end of the holder from which a lamp projects;

FIG. 2 is an end elevation of the holder, showing the end from which the lamp projects, but omitting the lamp;

FIG. 3 is a side elevational section of the holder of FIGS. 1 and 2, and

FIG. 4 is an end elevation opposite to that of FIG. 2.

A pair of lamp holders each like the illustrated electric lamp holder are designed to hold the respective end caps 13 of a tubular linear tungsten halogen lamp 11.

The lamp holder 10 comprises a cast non-metallic support 12 having a base portion 12a, a pedestal portion 12b, and a housing portion 12c. A metal contact 14 is mounted in a porcelain contact carrier 16 that is slidably mounted within the support 120 and is biased by a helical compression spring 18 towards the front end 20 of lamp holder 10 to engage an end contact (not shown) in end cap 13 of the lamp 11. The rear end of spring 18 is retained within the support 12 by means of a back plate 22 which is secured to support 12 by means of two screws 24. The contact 14 is crimped to an electric cable 25 which extends out from the back of the support 12, as shown in FIG. 2.

A heat sink for the lamp, which serves to dissipate excess heat from the end of the lamp, is provided by two heat-conductor metal members 26 and 28, which are respectively pivotally mounted on two pivot pins 30 and 32. The pins 30 and 32 are each in the form of a headed pin each with an extended projecting shank 31, 33, respectively, the shanks 31 and 33 projecting in front of the support 12 by a sufficient amount to allow the heat-conductor members 26 and 28, as well as pivoting on the shanks 31 and 33, to slide along them, so that the positions of the members 26 and 28 can be adjusted axially relative to the lamp axis (coincident with the axis of spring 18). This enables the members 26 and 28 to take up different axial positions to accommodate various lamp dimensions and/ or tolerances.

A helical compression spring 34 is connected between members 26 and 28 on inwardly projecting pins 35 and 37 beneath the pivot pins 30 and 32, to bias inwardly projecting end portions 36 and 38 of members 26 and 28 into engagement with flats (not shown) which are provided on the tubular lamp adjacent each end. The surfaces of the ends 36 and 38 of members 26 and 28 are convexly curved, as shown in FIG. 2, so that a sufiiciently good thermal contact is made with the flats on the lamp even in the event the flats are misaligned. The members 26 and 28 are of solid metal, so as to form good heatconductors to conduct heat away from the lamp.

To permit the insertion and/or withdrawal of lamp 11, a cam member 40 is rotatably mounted in support 12 and a flat portion 41 of cam member 40 extends between members 26 and 28. Cam member 40 is fitted with a release handle 42, secured by means of a retaining spring clip 44, whereby cam member 40 can be rotated to cam members 26 and 28 away from their respective lamp-engaging positions to permit insertion into *and/or withdrawal from the holder 10 of the end of the lamp 11.

The holder 10 can be used for different tubular tungsten halogen lamps of various lengths, a second similar holder being used for the other end of the lamp. Being mounted on the support 12, the heat-conductor members 26 and 28 should always be in the correct positions to act as heat sinks for the lamp end, to assist dissipation of excessive heat to the surrounding atmosphere, and maintain the lamp at an efiicient operating temperature.

The rear end of support 12 acts as a stop for lever 42, so that when the cam member 40 is rotated to cause the fiat portion 41 to open the members 26 and 28 it will move to just over dead centre position where it will be retained by the spring bias of members 26 and 28.

Finally, it should be mentioned that by incorporating the heat-conductor members 26 and 28 in the holder 10 it is only necessary to provide alternative mounting positions in a single lighting fitting for two holders such as holder 10 to accommodate different sizes of lamps in the same lighting fitting.

What is claimed is:

1. Lamp holder means for supporting a tubular electric lamp having at one end end cap means containing an electrical contact, comprising a stationary support (12) having a housing portion adapted to receive the end cap means, and a pedestal portion for supporting said housing portion;

means for energizing said lamp including a contact (14) carried by said housing portion for engaging the lamp end contact;

heat sink means for dissipating heat from said end cap means during energization of said lamp, comprising a pair of heat-conductive arms (26, 28) each pivotally connected with said pedestal portion for' pivotal movement about an axis parallel with the lamp axis, and spring means (34) biasing said arms together into engagement with and on opposite sides of said end cap means; and

cam means (40) movably connected with said support for releasing said heat-conductive arms from said end cap means, said cam means extending between said arms and initially having a retracted position in which said arms are in heat conductive engagement with said lamp end cap, said cam means being operable toward a released position for pivoting said arms out of engagement with said end cap.

2. Lamp holder means for supporting a tubular electric lamp having at one end end cap means containing an electrical contact, comprising a stationary support (12) having a housing portion adapted to receive the end cap means, and a pedestal portion for supporting said housing portion;

means for energizing said lamp including a contact (14) carried by said housing portion for engaging the lamp end contact;

heat sink means for dissipating heat from said end cap means during energization of the lamp, comprising a pair of heat-conductive arms (26, 28) each pivotally connected intermediate its ends with said pedestal portion for pivotal movement about an axis parallel with the lamp axis, said arms being adapted for heat-conductive engagement at one end with opposite sides of said end cap means; and

compression spring means cooperating with the other ends of said arms for biasing said armstogether into engagement with said end cap means.

3. Lamp holder means as defined in claim 2, wherein said means for energizing saidlamp comprises carrier means (16) for said contact, said carrier means being slidably connected with the housing portion of said support for sliding movement axially of the lamp to accommodate lamps of different lengths, and spring means bias 4 ing said contact carrier means axially toward the lamp end cap;

and further wherein each of said heat-conductive arms is mounted for axial sliding movement relative to its pivot axis.

4. Lamp holder means as defined in claim 2, wherein the end cap means of the tubular lamp includes flat portions;

and further wherein the ends of said heat-conducting arms adjacent said end cap means are convexly curved to afford sufficient thermal contact with the end cap fiat portions even in the event the flats are misaligned.

References Cited UNITED STATES PATENTS 3,390,372 6/1968 Kember et a1. 339-112 FOREIGN PATENTS 1,416,565 9/1965 7 France.

1,032,396 6/1958 Germany.

MARVIN A. CHAMPION, Primary Examiner J. H. McGLYNN, Assistant Examiner US. Cl. X.R. 

